Rough idle on a 89 Force 85hp. Video included.

[7501sl]

Im having an issue with my 89 Force 85 hp (856X9C) not running as smooth at idle as it did before. Before I could turn it on cold without it stalling. Now I have to give it some gas on the linkage or else it will stall. Once I do that it will run as shown in video. Compression is good and so is spark. No overheating issues. Block is COOL to the touch. I replaced the fuel lines, primer bulb, spark plugs, fuel pump gasket and diaphragm. I even removed fuel pump again to confirm I had installed everything correctly. I installed inline fuel filter between fuel pump and carb and replaced fuel water element. I had drained fuel tank and refilled with fresh premix at 50:1. I also cleaned pickup tube screen on the tank. Fuel recirculation was cleaned out. I didnt see any leak anywhere from fuel tank to carbs. Rpm is around 900 but fluctuates. Hard to tell EXACT rpm on that cheesey OEM rpm gauge. Idle was set at 1 1/4 turns out on all three carbs. I even dropped it down to 1 turn out to see if it would make a difference which it didnt. If I hold my hand over each carb long enough it will stall motor. The top carb is sucking in air ALOT more then the bottom two...not sure if this is normal. Anyway, any advice will be appreciated. Thanks:facepalm:


http://www.youtube.com/watch?v=qKA5BYFepjY&feature=channel_video_title

 

[jerryjerry05]

Re: Rough idle on a 89 Force 85hp. Video included.

Those front screw are not idle screws.They are air screws and should be about 1 and 1/8th turn out.
Idle is adjusted from the towershaft(see pic)#4#5 Should be 750-800 in gear in the water.About 1000 in the driveway.Try setting there and see if that helps.Clean the carbs.At the top of the Force section is a sticky by FrankA for linc and sinc.Do that next.J

 

[7501sl]

Re: Rough idle on a 89 Force 85hp. Video included.

View attachment 91949Those front screw are not idle screws.They are air screws and should be about 1 and 1/8th turn out.
Idle is adjusted from the towershaft(see pic)#4#5 Should be 750-800 in gear in the water.About 1000 in the driveway.Try setting there and see if that helps.Clean the carbs.At the top of the Force section is a sticky by FrankA for linc and sinc.Do that next.J

Thanks for the reply. Didnt get a chance to do anything to it today. However I did notice that alot and I mean ALOT of unburned fuel had leaked out the weepholes of the lower unit overnight. I read on another thread that theres the possibility that some primer bulbs might overwhelm the carbs. Im going to switch back to the OEM bulb (which is still good) and see if it makes a difference. Im kind of hesitant to start messing with the idle adjust, the carbs'link and sync. If there was no problems with idle and carbs BEFORE I replaced fuel lines, bulb and fuel pump gasket & diaphragm but now runs rough and starts hard afterwards it would stand to reason that I did something to upset smooth motor operation.....

 

[steveclv]

Re: Rough idle on a 89 Force 85hp. Video included.

I don't think you have touched the carbs yet right?

I'd drop the fuel bowls on each and clean them and use a carb cleaner to blow out each jet and orifice. I'd also pull the pin that holds the float and clean the needle valves - check for wear at the same time. A stuck needle valve (from a bit of old debris) could cause the fuel level to be too high meaning that carb could be running way too rich - one way to check is to see if the idle mixture screw has any effect on that carb. If not then that's likely the cause.

 

[7501sl]

Re: Rough idle on a 89 Force 85hp. Video included.

I don't think you have touched the carbs yet right?

I'd drop the fuel bowls on each and clean them and use a carb cleaner to blow out each jet and orifice. I'd also pull the pin that holds the float and clean the needle valves - check for wear at the same time. A stuck needle valve (from a bit of old debris) could cause the fuel level to be too high meaning that carb could be running way too rich - one way to check is to see if the idle mixture screw has any effect on that carb. If not then that's likely the cause.

I'll do as you suggest. One thing I forgot to mention that may be relevent is that before I changed fuel lines, primer bulb, etc NO fuel ever leaked out of any of the carbs when I tilted the motor up. Now it when I tilt it up fuel leaks out on all three carbs.....

 

[stanfordwest]

Re: Rough idle on a 89 Force 85hp. Video included.

i would re check the tightness on the lines goin to carbs then

 

[GoldLS1]

Re: Rough idle on a 89 Force 85hp. Video included.

I'll do as you suggest. One thing I forgot to mention that may be relevent is that before I changed fuel lines, primer bulb, etc NO fuel ever leaked out of any of the carbs when I tilted the motor up. Now it when I tilt it up fuel leaks out on all three carbs.....

Ahaha.... well it's not that funny, but I am currently having the same issue and did the exact same thing - swap out the fuel lines and tank. Hope to get the boat back out this weekend and go back thru all the lines, finishing replacing the rest of them (even between the carbs), clean the carbs, bowl, and float. Then give it another whirl. Stinks my motor was running great before

Be sure to post back if you figure it out... I'll do the same

 

[steveclv]

Re: Rough idle on a 89 Force 85hp. Video included.

I'm no expert but we seem to have seen quite a few similar issues and it often occurs after someone has played with the fuel lines - replacing them etc.

From my limited experience, the problem (in my case) was that after I cured one problem by cleaning the small screen in the tube that goes into the tank, and replacing all of the fuel hoses and pump diaphragm, is that a small piece of debris got into the needle valve and that caused the top carb (in my case) to flood. Whilst my idle was not too bad (maybe cos it's a 4 cylinder and not 3 - dunno) but when running it wasn't very happy.

I dropped the carb, cleaned the needle valve, reset the float height and added a small inline filter between the carbs and the fuel pump and it made a huge difference. In my 19' Bayliner I am now at 43mph GPS at WOT which I think is pretty much spot on.

 

[huskerdaninva]

Re: Rough idle on a 89 Force 85hp. Video included.

The little inline filters are wonderful cheap insurance on an outboard. Likely the best $4.99 or so you'll ever spend...

 

[GoldLS1]

Re: Rough idle on a 89 Force 85hp. Video included.

I have a filter before the bulb. The only stuff I messed with was pre-filter. Filter glass is clean. Still could have gotten by I guess.

 

[7501sl]

Re: Rough idle on a 89 Force 85hp. Video included.

Man, Im such a newbie. I rechecked compression and spark today and found Im not getting any spark on top cylinder. I dont get it I had checked it 3 weeks ago and it was fine. So in the video my outboard is only running on 2 cylinders. Coil is the likely culprit? After all 2 & 3 are firing. I didnt have time to switch coils. But the wires for #1 and #2 look like they come out of the same side of the same power pack so hopefully its just the coil. I did however perform the "poor man's stator test" and looked underneath the flywheel at the stator with a flashlight. The attached pic shows how it looked all the way around. No loose wires. Nothing looked burned or corroded in fact it looked new. If the module(s) and stator were bad wouldnt more then just one cylinder not recieve spark?

 

[7501sl]

Re: Rough idle on a 89 Force 85hp. Video included.

On Saturday I replaced power pack for #1 and #2 and got spark back. I ran boat on Sunday again only to find I had lost spark again on #1. What else should I look at?

 

[jerryjerry05]

Re: Rough idle on a 89 Force 85hp. Video included.

outboard ignition.com has test procedures for Force motors.It will tell you how and what equipment you will need.
If the stator was going bad it could stop spark on 1 or 2 or all 3.The trigger could be going bad.
Quick checks,the regulator could be going bad.Unhook it and see if it causes/stops.Unhook the tach and see if that helps.J

 

[7501sl]

Re: Rough idle on a 89 Force 85hp. Video included.

outboard ignition.com has test procedures for Force motors.It will tell you how and what equipment you will need.
If the stator was going bad it could stop spark on 1 or 2 or all 3.The trigger could be going bad.
Quick checks,the regulator could be going bad.Unhook it and see if it causes/stops.Unhook the tach and see if that helps.J

Loose wire. Looks like I needlessly spent money on a power pack. Oh well, at least I'll have it when I need it. Thanks, Jerry.

 

[exp2000]

Re: Rough idle on a 89 Force 85hp. Video included.

I'd drop the fuel bowls on each and clean them and use a carb cleaner to blow out each jet and orifice. I'd also pull the pin that holds the float and clean the needle valves - check for wear at the same time. A stuck needle valve (from a bit of old debris) could cause the fuel level to be too high meaning that carb could be running way too rich - one way to check is to see if the idle mixture screw has any effect on that carb. If not then that's likely the cause.

Sorry to hijack this, but it looks like that my bottom carb might have this issue, since turning the screw in or out does not have any effect. And the bottom spark is wet and has black buildup, other two are spot clean. Can this be done without taking the carb of?

 

[7501sl]

Re: Rough idle on a 89 Force 85hp. Video included.

Just had to stop by and say that I took off and cleaned my carbs this past weekend. ALOT easier to do then I thought. It surely needed cleaning. The #3 fuel bowl looked like it had fuel bowl gasket fragments inside of it. Engines now running tip top. If a mechanical noob like me can do it then anyone can. Took me about 3 hours to do (I took my time). And to think I was about to pay a boat shop $375 to do it for me lol

 

[goodtimesfishing]

Re: Rough idle on a 89 Force 85hp. Video included.

And just think....if you would have taken it to the boat shop and paid $375, the problem would still be there and a new issue would be popping up! Just kidding.....but it does seem like I always here of people spending a fortune at boat shops and the problem still exist. When you take the time and do it yourself, you relize that it is not that hard if you just educate yourself a little and take your time. Congrats on fixing your problem.

 

[bub080]

Re: Rough idle on a 89 Force 85hp. Video included.

not one posting ,said any thing about ethenol gas which is akiller to boat motors, small engines,gas lines,plastic gas cans,all gas stations have to sell gas with 10%ethenol the only ones that can sell non ethenol gas are marinas ,air fields i have a 85hp force engine and the same problems that the posters have listed i still have check your gas,i recently spent 450.00$ on my engine and still have same problems

 

[tater76]

Re: Rough idle on a 89 Force 85hp. Video included.

Ethanol free gas is available at some stations throughout the US, not just air fields, and marinas. I have a few around my home town. The stations often advertise this on their billboard. It is a little higher priced, but worth the money to run in the older outboards. Look around town, or even google it to find a location.

 

[goodtimesfishing]

Re: Rough idle on a 89 Force 85hp. Video included.

I have a station with ethenal free gas nearby. If I wouldn't have read about it on a local fishing site, I would not have even known! They don't always advertise it. In fact I use to drive by that station and think why would anyone buy there gas there? they are about .10 cents more a gallon!! Now I understand why it is .10 cents more a gallon and have no problem paying it!!! Should be able to goggle and find it near you.